Please note that if the special character device nodes /dev/twa? and /dev/twe? do not exist, or exist with the incorrect major or minor numbers, smartctl will recreate them on the fly. Typically /dev/twa0 refers to the first 9000-series controller, /dev/twa1 refers to the second 9000 series controller, and so on. Likewise /dev/twe0 refers to the first 6/7/8000-series controller, /dev/twa1 refers to the second 6/7/8000 series controller, and so on.